Share This

Byproducts of soybeans include soluble carbohydrates that can be turned to succinic acid when metabolized by E. coli bacteria engineered at Rice University. Succinic acid is used in a variety of products, including plastics, textiles, drugs, solvents and food.

Related Articles

Succinic acid, traditionally drawn from petroleum, is one focus of research by Rice chemists George Bennett and Ka-Yiu San. In 2004, the Department of Energy named succinic acid one of 12 "platform" chemicals that could be produced from sugars by biological means and turned into high-value materials.

Several years ago, Rice patented a process by Bennett and San for the bio-based production of succinic acid that employed genetically modified E. coli bacteria to convert glucose into succinic acid in a way that would be competitive with petroleum-based production.

The new succinate process developed by Bennett, San and Chandresh Thakker and reported recently in Bioresource Technology promises to make even better use of a cheap and plentiful feedstock, primarily the indigestible parts of the soybean.

"We are trying to find a cheaper, renewable raw material to start with so the end product will be more profitable," said Thakker, a research scientist in the Bennett lab at Rice's BioScience Research Collaborative and lead author of the study. "The challenge has been to make this biomass process cost-competitive with the petrochemical methods people have been using for many years."

Bennett feels they have done that with soybean-derived feedstock as an inexpensive source of the carbon that microorganisms digest to produce the desired chemical via fermentation. "A lot of people use plant oils for cooking -- corn or soybean or canola -- instead of lard, as they did in the old days," he said. "The oils are among the main products of these seeds. Another product is protein, which is used as a high-quality food.

"What's left over is indigestible fiber and small carbohydrates," said Bennett, Rice's E. Dell Butcher Professor of Biochemistry and Cell Biology. "It's used in small amounts in certain animal feeds, but overall it's a very low-value material."

The Rice researchers are changing that with the help of E. coli bacteria engineered to process soy meal that generally gets discarded. Certain microbes naturally produce succinic acid from such feedstock, but manipulating E. coli's metabolic pathways (by eliminating pathways that produce other chemicals like ethanol, for instance) can make it far more efficient.

Expanding on their success in producing succinic acid from glucose, the new microbes are engineered to metabolize a variety of sugars found in soybean meal. The theoretical ideal is a 1:1 ratio of feedstock (the extracted sugars) to product, which they feel is achievable by industry. In the lab, under less controlled conditions, they still found the process highly efficient. "We're demonstrating a very high yield," Thakker said. "We're achieving in a flask a non-optimized formation of succinate that is close to the theoretical goal."

Bennett said his lab has been looking at soybeans for nearly three years. "We're always interested in low-cost feedstock," he said. "We were able to get a connection with a soybean group that is very interested in technologies to make better and more profitable use of their crop.

"There's a fair amount of oilseed residuals available, including cottonseed carbohydrates, that are not used for any high-value product, and we're in the space of microbial engineering to enable these sorts of materials to be used in a good way," he said.

Story Source:

The above story is based on materials provided by Rice University. Note: Materials may be edited for content and length.

More From ScienceDaily

More Matter & Energy News

Featured Research

Mar. 3, 2015 — By examining the forces that the segments of mosquito legs generate against a water surface, researchers have unraveled the mechanical logic that allows the mosquitoes to walk on water, which may ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — Major cities in the UK are falling behind their international counterparts in terms of their use of smart technologies, according to a new study. The research has found that smart cities in the UK, ... full story

Mar. 3, 2015 — Scientists have explored friction at the microscopic level. They discovered that the force generating friction is much stronger than previously thought. The discovery is an important step toward ... full story

Mar. 3, 2015 — Micro-drones are already being put to use in a large number of areas: These small aircraft face extensive requirements when performing aerial observation tasks or when deployed in the field of ... full story

Mar. 3, 2015 — Recent research contributes to the effort to determine the nature of dark matter, one of the most important mysteries in physics. As indirect evidence provided by its gravitational effects, dark ... full story

Mar. 3, 2015 — Physicists have shown for the first time that electrons in graphene can be moved along a predefined path. This movement occurs entirely without loss and could provide a basis for numerous ... full story

Featured Videos

Forensic Holodeck Creates 3D Crime Scenes

Reuters - Innovations Video Online (Mar. 3, 2015) — A holodeck is no longer the preserve of TV sci-fi classic Star Trek, thanks to researchers from the Institute of Forensic Medicine Zurich, who have created what they say is the first system in the world to visualise the 3D data of forensic scans. Jim Drury saw it in operation.
Video provided by Reuters

Solar Plane Passes New Test Ahead of World Tour

AFP (Mar. 2, 2015) — A solar-powered plane made a third successful test flight in the United Arab Emirates on Monday ahead of a planned round-the-world tour to promote alternative energy. Duration: 01:05
Video provided by AFP

Electric Hydrofoiling Watercraft Delivers Eco-Friendly Thrills

Reuters - Innovations Video Online (Mar. 2, 2015) — The Quadrofoil is a high-tech electric personal watercraft that its makers call a &apos;sports car for the water&apos;. When it hits 10 km/h, the Slovenian-engineered Quadrofoil is lifted above the water onto four wing-like hydrofoils where it &apos;flies&apos; above the surface with minimal water resistance. Matthew Stock reports.
Video provided by Reuters

Related Stories

Mar. 20, 2013 — Proteins found in soybeans could inhibit the growth of colon, liver and lung cancers. Soybean meal is a bi-product following oil extraction from soybean seeds. It is rich in protein, which usually ... full story

Aug. 22, 2012 — Scientists have unveiled new technology intended to move soybeans, second only to corn as the top food crop in the U.S., along the same use-to-all path of corn and crude oil as a raw material for a ... full story

May 9, 2012 — Soybeans soaking in warm water could become a new "green" source for production of a cancer-fighting substance now manufactured in a complicated and time-consuming industrial process, ... full story

Jan. 27, 2011 — Scientist investigated the response of two soybean varieties in row widths of 7.5, 15, and 30 inches at four seeding rates. They measured emergence rates of soybean, growth, yield components, and ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.